Base Currency
The base currency, or denominator, is the first in a currency pair, the second currency is the quoted currency. The value of the quoted currency is expressed in terms of one unit of the base currency. In euro/dollar, for example, the value of the dollar is quoted or expressed in terms of one euro. With Canadian dollar/U.S. dollar, the value of the U.S. dollar is quoted in terms of one Canadian dollar.
See also: Exchange Rate